Tobacco lathing machine



Aug. 12,1958 J. L. KRIST TOBACCO LATHING MACHINE 5 Sheets-Sheet 1 Filed June 1. 1955 INVENTOR JOSEPH L. KR/ST ATTORNEYS 5 Sheets-Sheet 2 J. L. 'KRIST TOBACCO LATHING MACHINE INVENTOR :JOSEPH L KR/ST ATTORNEYS Aug. 12, 1958 Filed June 1, 1955 N Uri Aug. 12, 1958 J. L. KRIST TOBACCO LATHING MACHINE 3 Sheets-Sheet 3 Filed June 1, 1955 INVENTOR JOSEPH L. KR/ST ATTORNEYS States Paten Oil-C6 2,847,130 Fatented Aug. 12, 1.958

bask

TOBACCO LATHING MA'CHINE Joseph L. Krist, Broad Brook, Conn.

Application June 1, 1955, Serial No. 512,451

9 Claims. (Cl. 2145.5)

This invention relates to tobacco lathing machines for automatically inserting laths through the stalks of tobacco plants to impale the plants on the laths for hanging during drying and curing.

This application is a continuation in part of my copending applications Serial Nos. 336,075 filed February 10, 1953, for a tobacco lathing machine, now Patent No. 2,713,427, and 411,401 filed February 19, 1954, now abandoned, for a tobacco lathing machine.

An object of the present invention is to provide a tobacco lathing machine having improved means for supporting the stalks during piercing thereof preparatory to inserting a lath therethrough, thereby avoiding darnage and mutilation of the plants and stalks due to excessive bending or twisting of the stalks during the piercing and impaling operations.

Another object is to provide means for supporting the stalks during the piercing and impaling operation, which supporting means are adjustable in order to accommodate stalks of varying diameters.

Another object is to provide a plurality of means for supporting the stalks during the piercing and impaling operation, which supporting means are self-adjustable independent of each other so that stalks of varying sizes may be accommodated simultaneously.

Other objects will he in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

In the drawings: I

Figure 1 is a plan view of the machine constructed in accordance with the present invention;

Figure 2 is a fragmentary front view of the machine;

Figure 3 is a fragmentary side view of the positioning, supporting and piercing means;

Figure 4 is an enlarged fragmentary front view of a portion of Figure 2;

Figure 5 is an enlarged fragmentary plan view of the supporting and piercing means and lath-inserting means shown in Figure 1;

Figure 6 is an enlarged fragmentary front view of the machine in the area of the holding, supporting, and piercing means.

Referring to the drawings, and more particularly to Figure 1, the machine embodying this invention consists of a chassis 2 with rear wheel 3 and front wheels 4 and 5. A motor 10 supported on the chassis 2 is connected by means of the main gearbox 11 and the rear wheel drive shaft 12 to the rear wheel gear box 13, which in turn is connected by suitable means to the rear wheel 3, thus providing for the movement of the machine along the ground. Also connected to the motor 10 is a compressor 14 which is supplied with a suitable fluid, preferably air, to a tank 15. The compressor 14 provides M a medium for energizing cylinders 16 and 17, the purpose of which will be explained hereinafter. The main shaft 18 extends from the main gear box 11 and transmits rotative motion from the motor 10 to a pulley 19 mounted on and rotating with the main shaft 18. The pulley 19 is connected by means of suitable belting to a pulley 20 to impart rotative motion to said pulley 20 and thus provide the power for the lath-impaling means as hereinafter described.

Also mounted on the chassis 2 and extending forwardly therefrom at a convenient height above the ground are arms 21 on which are mounted a plurality of holders 22a and 22b. The leftward pair of holders as shown in Figure 1 is in the position assumed when a stalk has been inserted in and is being retained by the holders. The remaining holders are in the position to receive a stalk. When a stalk is inserted between the holders and the stalk is urged rearwardly, holder 22a will be rotated counterclockwise, and holder 22b will be rotated clockwise. Suitable stops are provided to limit the rotation of the holders to approximately 45 degrees. Holding spring 23 mounted on holder 22b urges the stalk into the V-shape-d retention area in holder 22a and said spring further provides a force of sufficient strength to maintain the holders in the closed position because of the oifset of the pivotal axes of holders 22a and 2212 with the force line between said spring 23 and the stalk. Located below the holders 22a and 22b and mounted on the chassis 2 are a plurality of aligning bars 24 which provide in conjunction with the holders a means for maintaining the stalks in vertical alignment during the piercing operation. One such alignment bar is provided for each pair of holders. The combination of the holders 22a, 22b and the aligning bars 24 will be hereinafter referred to as the first supporting means.

Also mounted on chassis 2 is a control valve 30 constructed to operate in conjunction with a suitable hydraulic arrangement to provide means for directing the compressed fluid from the compressor 14 to the cylinder 16, when the control lever 31 of said valve is urged in one direction a suflicient distance. Said control valve and hydraulic arrangement are so designed that further movement of the control lever'31 in the same direction will direct fluid flow from the compressor 14 to another cylinder 17. The importance of this sequence of operation is explained below.

With reference to Figures 3, 4, 5 and 6, there are provided retractable supporting means 35 which are brought into engagement with the stalks of the plants after they have been inserted in the holders for supporting the stalk against twisting and lateral bending or deflection during the piercing and lathing operations. The retractable supporting means 35 include a plurality of supporting bars or brackets 42 (one for each station) transversely mounted on and fixed to a positioning shaft 44 which is located above the chassis 2 approximately midway between the upper holders 22a, 22b and the lower aligning bars 24. The shaft 44 carrying the bars 42 is arranged to be actuated longitudinally by cylinder 16, as will be hereinafter described.

Mounted on the bars 42 are forwardly projecting jaws 36, 37 which are arranged to engage the rear side and front side of the stalk when the shaft 44 is thrust to the left as viewed in the drawings. In the preferred embodiment, the jaws 36, 37 are pivotally mounted on the bars 42 so as to provide a variable openingwidth and a uniform restraining action on stalks of varying thicknesses.

To this end, jaws 36, 37 are fixed to intermeshed gears 40, 41 which are rotatably mounted on the bars 42.

The rotational cycle of the jaws 36, 37 is partially accomplished by tension spring 45 which is connected to jaw 36 and supporting bar 42 in such a manner as to urge the jaw 36 in a clockwise direction, which through gears 40, 41 will urge jaw 37 in a counterclockwise direction to separate the jaws to the open position. Control lever 46, rotatively mounted on supporting bar 42, has a projecting arm 47 which, when control lever 46 is moved in a counterclockwise direction, will engage jaw 36 so as to move said jaw in a counterclockwise direction against the force of spring 45. The movement of jaw 36 in this direction will, through gears 48 and. 41, cause clockwise movement of jaw 37 and thus the jaws will be closed. At the rearward end of lever 46 there is attached a tension spring 48 which, in turn, through coupling 49, is connected to control shaft 51. The coupling 49 has a lateral slot 50 which enables the coupling to move to the left the length of the slot prior to placing tension on spring 43 and further allows said coupling 49 to telescope into spring 48 when the coupling is moved to the right. The purpose of this free travel arrangement is described below.

Referring to Figures 3, 4 and 5, the piercing mechanism is composed of piercer elements 60 and 61 having a U-shaped cross section to permit the travel of the lath therethrough when the piercers are in cooperating position. Piercers 6i) and 61 are mounted on and fixed to piercer shafts 62 and 63, respectively. Intermeshed piercer control gears 64 and 65 are connected to the ends of piercer shafts 62 and 63, respectively. A spring 66 is afiixed to piercer control gears 64 and 65 in such a manner as to urge gear 64 in a clockwise direction and gear 65 in a counterclockwise direction, as viewed in Figure 3, thus through shafts 62 and 63, urging the piercers 60 and 61 to a closed position. Shaft 62 has mounted thereon and fixed thereto a lever 67 which cooperates with cam 68 to prevent spring 60 from rotating gears 64, 65 when piercer shaft 62 is in the lateral position shown in Figure 4. When shaft 62 is urged to the left the slope of cam track 69 will permit clockwise rotation of lever 67, as viewed in Figure 3, thus permitting shafts 62, 63 to rotate through the action of spring 66 and gears 64, 65 to the closed position shown in Figure 6. In practice it has been found desirable to provide a cam such as cam 68 for each station of the machine in order to reduce twisting moments in the shaft 63.

Figure 6 best illustrates the novelty and usefulness of this invention. In Figure 6 the stalk as shown by the dotted line has been inserted in the holders 22a and 22b and is being retained thereby. The supporting jaws (only jaw 37 is shown) have been closed about the stalk and the piercer elements 60 and 61 have been closed and positioned for piercing. At this point in the operation it can be seen that the holders 22a and 22b and the alignment bar 24 comprising the first supporting means provide a backing for the piercers 6t and 61 in order to maintain the stalk in a vertical position during piercing. The variable jaws of the second supporting means 35 are gripping the stalk with a firm force imparted by spring 48. This gripping action, when initially applied, will correct any misalignment of the stalk with the piercers in order to assure that the piercing elements 60, 61 will penetrate the center of the stalk in order to minimize twisting moments of the stalk during piercing. After the gripping action is completed the jaws will prevent any axial twisting or transverse movement of the stalk during the piercing and lathing thereof thus preventing mutilation of the stalk. It can be seen that a firm retention and support is provided at three points on the stalk to prevent undesirable movement of the stalk in any direction during the piercing and lathing.

In the operation of the machine as described, stalks.

of tobacco will be placed by the operator or his helpers within the area provided between holders 22a and 22b and then manually urged to the rear, the stalks then being held in position for subsequent piercing and lathing operations. To begin the subsequent operations, the operator will urge control lever 31 in the proper direction a distance suflicient to direct the flow of hydraulic medium from the compressor 14 to the cylinder 16. The energizing of cylinder 16 will result in the movement of shaft 75 to the left. Shaft 75 is connected by suitable means to control shaft 51. Shaft 75 is further connected to positioning shaft 44 by means of a plate 78 and latch 79.

Latch 79 is maintained in engagement with shaft 75 by means of spring 80. Thus movement of shaft 75 to the left will also cause movement of shafts 51 and 44 in the same direction. As shaft 44 is moved to the left, it carries with it supporting bar 42, to which are attached the second supporting means 35. When positioning shaft 44 has moved a predetermined distance to the left, latch 79 will engage cam 81, causing latch 79 to disengage from shaft 75 so that further movement of shaft 75 will not cause further movement of shaft 44. At this point the second supporting means 35 are in position to engage the stalks held in position by holders 22a and 22b and aligning bars 24. The lateral position of cam 81 is adjustable to permit the varying of the leftmost position of the second supporting means 35.

The control lever 46, when shaft 75 is in its rightmost position, is in engagement with cam 82, which cam maintains lever 46 in its leftmost position, thus by the projecting arm 47 maintaining the jaws 36, 37 in a closed position. As shaft 75 moves to the left, lever 46 is disengaged from cam 82, permitting lever 46 to rotate in a clockwise direction. This rotation of lever 46 is caused by spring 45 which, as lever 46 is disengaged from cam 82, urges the jaw 36 of the supporting means in a clockwise direction. This movement of jaw 36 through the intermeshing of gears 40 and 41 causes both jaws 36 and 37 to open in their initial forward travel with positioning shaft 44. Following the disengagement of positioning shaft 44 from shaft 75, shaft 75 continues to move to the left, as viewed in Figure 5, carrying with it the control shaft 51. Sufiicient movement of control shaft 51 will, through spring 48, cause control lever 46 to be rotated in a counterclockwise direction, thus urging jaw 36 in a counterclockwise direction against the force of spring 45 and, through the intermeshing gears 40 and 41, cause a clockwise movement of jaw 37 so as to result in the engagement and supporting of the stalks by the jaws 36, 37. If no stalk were present the jaws 36, 37 would be rotated to the limit of the teeth in the gears 40 and 41. However, it can readily be seen that the spring 48 will permit the lesser counterclockwise motion of lever 46 and thus the jaws, if a stalk is present to create an obstacle to complete closing of the jaws. Thus, each of the plurality of supporting means will in the same operation receive and firmly support stalks of varying diameters. This feature has the advantage of providing a plurality of variable supporting means whereby the diameter of a stalk will not determine the extent of the engaging motion of any supporting means other than the supporting means associated with the specific stalk, thus providing a simultaneous yet equally satisfactory supporting of stalks of varying diameters.

Further movement of control lever 31 in the same direction will cause hydraulic medium to be directed from the compressor 14 to the cylinder 17. When cylinder 17 is energized thereby, shaft will be urged in a leftward direction as viewed in Figures 2, 4 and 5. Shaft 90 is pivotally connected to latch 91, which is so mounted in plate 92 that leftward movement of shaft 90 will cause latch 91 to be rotated in a counterclockwise direction to engage plate 93. Plate 92 is affixed to plate 108 so that the leftward movement of shaft 90 will urge plate 103 to the left. The piercer control gears 64, 65 are rotatably mounted on plate 108 so that, as plate 108 moves to the left, it carries with it piercer shafts 62, 63 and piercers 60, 61. This initial leftward movement of shaft 62 results in spring 66 closing the piercers 60, 61, inasmuch as the slope of cam track 69 allows lever 67 to rotate as the lever moves forward with shaft 62. Shaft 90 is stopped in its leftward travel at a point where the piercers are in a position to pierce the stalk, but no piercing is accomplished at this stage of the operation. At this stage lever 67 is positioned on cam 68 at the intersection of tracks 69 and 70.

Also connected to shaft 90 is lever 94 which, as it moves to the left with shaft 90, rides over cam 96 mounted on the chassis 2. The resultant forward motion of lever 94 engages clutch 95. Engagement of clutch 95 results in the rotative action of pulley 20 being transmitted by suitable belting 97 to the eccentric disc 98, which is rotatably mounted on chassis 2. As disc 98 rotates, it causes through its eccentricity and linkage 99 a reciprocal motion in lathing shafts 100 and 101. These shafts have in turn mounted thereon and travelling therewith jaws 102 which, through linkage 103, are caused to open as lathing shafts 100, 101 are moved to the right, and caused to close when shafts 100, 101 are moved to the left. Thus the lath is urged to the left in stepby-step fashion. As shaft 101 moves to the left, it carries with it plate 93 which, in its forward movement, engages latch 91 by means of shoulder 105. The movement of plate 93 in a leftward direction causes the movement plate 92, through the action of shoulder 105 and latch 91. Plate 92 is fixed to plate 108 which is slidahly mounted under plate 93. Thus, plate 108 will move to the left as plate 93 moves to the left. As gears 64, 65 are connected to plate 108, leftward movement of plate 108 causes leftward movement of shafts 62 and 63, which in turn causes the piercers 60 and 61 to penetrate the stalks. During the initial leftward movement of plate 108, lever 67 travels along the fiat cam track 70 of cam 68. When the stalks have been pierced, the lever 67 will ride down on cam track 71 of cam 68 to open the piercers slightly in order to permit unobstructed passage of the lath. This slight opening of the piercers after piercing allows for varying sizes of lath and thus precludes the necessity for maintaining a close tolerance on the diameter of the lath. Obviously a dimensional relationship between the overall length of the cam 68 and the initial stroke of shaft 101 must be built into the pertinent components of the machine. Thus the initial leftward movement of the lath-holding jaws 102, 103, results in the piercers 60, 61 penetrating the stalks and then opening slightly in preparation for receiving the lath. The length of stroke of the shafts 100, 101 and the placement of the lath in the jaws 102 is such that the lath will not reach the first stalk until after the stalk has been pierced and the piercers opened slightly. Inasmuch as plate 93 is slidahly mounted on plate 108, further reciprocal motion of plate 93 will not result in further movement of plate 108, nor thusly, the piercers 60, 61.

When, through the reciprocating action imparted to the lath-retaining jaws 102, 103, the lath has been inserted through all of the stalks, the control lever 31 is urged in the opposite direction, thus disengaging the clutch mechanism 95 to prevent further reciprocating movement of jaws 102, 103. This movement of lever 31 also tie-energizes cylinder 17, causing shaft'90 to be urged to the right which, through latch 91 and plate 92, will result in plate 108 moving to the right, carrying with it shafts 62 and 63 and thus drawing the piercers out of the stalk. As shaft 62 is urged to the right, lever 67 engages cam track 69 of cam 68, resulting in a counterclockwise movement of the shaft, as viewed in Figure 3, which through the action of intermeshing gears 64, 65 causes the piercer elements to open to the position shown in Figure 1. Further movement of lever 31 in the same direction de-energizes cylinder 16 causing shaft 75 to move to the right, carrying with it coupling 49. This movement of coupling 49 releases tension on spring 48 permitting control lever 46 to be moved in a clockwise direction as spring 45 urges supporting jaw 36 in a clockwise direction. As jaw 36 moves in a clockwise direction, jaw 37 will be urged in a counterclockwise direction through intermeshing gears 40, 41, thus opening the jaws 36, 37 to release their hold on the stalk. Further movement of shaft 75 to the right will cause shaft 76 to engage the rightmost portion of slot 83 in plate 78 to cause movement of positioning shaft 44 to the right. As shaft 44 moves to the right, it carries with it supporting bar 42 on which are mounted the second supporting means 35. As the supporting means 35 moves to the right, lever 46 engages cam 82, causing lever 46 to be urged in counterclockwise direction which, through the engagement of projecting arm 47 with jaw 36, causes jaws 36 and 37 to return to closed position. As lever 46 is urged in a counterclockwise direction, the coupling 49 telescopes into the spring 48 by means of slot 50. The extent of travel and initial positioning of the supporting means 35 and piercers 60, 61 is such that, when both are in the rightmost position, the supporting means surrounds the uppermost piercer to protect the operator. In the sequence of operations, the supporting means is urged to the left before the piercing means. Thus the operator is protected from the piercers by the supporting means whenever he would be placing his hands near the piercers. To disengage the stalks from the holders 22a and 2212, a stalk need merely be urged forward, which will cause the rotation of the holders 22a and 22b to positions shown in Figure l and in which position the holders are ready to receive the next load of stalks.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 7

It is also to be understood that the language used in the followingclaims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim:

1. In a tobacco lathing machine of the type having a series of horizontally spaced aligned holders for receiving and holding the stalks of tobacco, stalk piercers mounted below said holders and movable relative thereto to penetrate stalks depending from the holders, and means for moving a lath endwise through the apertures made by said piercers, the combination therewith of means for embracing and providing lateral support for the stalks in the region subjected to stress by the piercers comprising a shaft mounted for reciprocation longitudinally of the aligned holders, a bracket fixed to and projecting from the shaft adjacent but below each holder adjacent the piercers, a pair of jaws mounted on each of the brackets for movement therewith into and out of engagement with stalks depending from the holders, and means for reciprocating the shaft following a piercing and lathing operation.

2. In a tobacco lathing machine of the type having a series of horizontally spaced aligned holders for receiv ing and holding the stalks of tobacco, stalk piercers mounted below said holders and movable relative thereto to penetrate stalks depending from the holders, and means for moving a lath endwise through the apertures made by said piercers, the combination therewith of means for embracing and providing lateral support for the stalks in the region subjected to stress by the piercers comprising a shaft mounted for reciprocation longitudinally of the aligned holders, a bracket fixed to and projecting from the shaft adjacent but below each holder, a pair of jaws pivotally mounted on each of the brackets for movement therewith into engagement with the stalks and resilient means urging the jaws into engagement with the front and back of the stalks.

3. In a tobacco lathing machine of the type having a series of horizontally spaced aligned holders for receiving and holding the stalks of tobacco, stalk piercers mounted below said holders and movable relative thereto to penetrate stalks depending from the holders, and means for moving a lath endwise through the apertures made by said piercers, the combination therewith of means for embracing and providing lateral support for the stalks in the region subjected to stress by the piercers comprising a shaft mounted for reciprocation longitudinally of the aligned holders, a bracket fixed to and projecting from the shaft adjacent but below each holder, intermeshing gear means mounted on each bracket, a pair of jaws mounted on said intermeshing gear means for pivotal movement in opposite directions, means urging the jaws to closed position, means for opening the jaws, and means for actuating the last-named means and for moving the shaft in sequence.

4. In a tobacco lathing machine of the type having a series of horizontally spaced aligned holders for receiving and holding the stalks of tobacco, stalk piercers mounted below said holders and movable relative thereto to penetrate stalks depending from the holders, and means for moving a lath endwise through the apertures made by said piercers, the combination therewith of means for embracing and providing lateral support for the stalks in the region subjected to stress by the piercers comprising a shaft mounted for reciprocation longitudinally of the aligned holders, a bracket fixed to and projecting from the shaft adjacent but below each holder, intermeshing gear means mounted on each bracket, a pair of jaws mounted on said intermeshing gear means for pivotal movement in opposite directions, spring eans urging the jaws to closed position, means for reciprocating the shaft between a position where the jaws engage the stalks and a position where the jaws are spaced from the stalks, and means for opening the jaws during movement of the shaft.

5. A tobacco lathing machine comprising a plurality of first stalk positioning means disposed in a line, each of said positioning means including a pair of vertically spaced positioning arms and a pair of L-shaped brackets pivotally supported on the upper arm of each pair for rotation from a stalk receiving position to a stalk holding position responsive to the insertion of a stalk therein, second stalk positioning means associated with each first stalk positioning means having outwardly diverging surfaces adapted to engage the front and back of a stalk at a point between the positioning arms of a pair, means for moving each stalk holder between its stalk engaging position from a point longitudinally spaced therefrom, piercers including a pair of separable piercing members associated with each second stalk positioning means, means for moving said piercers into and out of engagement with said stalks at a point immediately adjacent the diverging surfaces of each of the second stalk positioning means, means associated with said piercer moving means for bringing the piercing members together as they approach the stalks and for separating them as they withdraw from the stalks, means for driving the piercers into the stalks at the point of engagement therewith to form apertures therein between the piercing members of each pair, means for feeding a lath through the apertures in the several stalks, and means for moving said second positioning means away from the stalks after a piercing and lathing operation.

6. In a tobacco lathing machine of the type having a series of horizontally spaced aligned holders for receiving and holding the stalks of tobacco, stalk piercing means mounted below said holder-s and movable relative thereto to penetrate stalks depending from the holders, and means for moving a lath endwise through the apertures made by said piercing means, the combination therewith of means associated with each holder for embracing and providing lateral support for the stalks in the region subjected to stress by the piercing means mounted on the machine for reciprocation as a unit longitudinally of the aligned holders, the embracing and supporting means each including a plurality of members mounted for movement relative to each other into and out of stalk engagement, and means to move the members of each of said embracing and supporting means into stall; engagement in response to movement of the embracing and supporting means longitudinally of the aligned holders.

7. In a tobacco lathing machine of the type having a series of horizontally spaced aligned holders for receiving and holding the stalks of tobacco, stalk piercing means mounted below said holders and movable relative thereto to penetrate stalks depending from the holders, and means for moving a lath endwise through the apertures made by said piercing means, the combination therewith of means for embracing and providing lateral support for the stalks in the region subjected to stress by the piercing means comprising a pair of jaws disposed below each holder adjacent the piercing means and engageable on the opposite sides of a stalk depending from the holder, and means mounting the pairs of jaws on the machine for reciprocation longitudinally of the aligned holders.

8. In a tobacco lathing machine of the type having a series of horizontally spaced aligned holders for receiving and holding the stalk-s of tobacco, stalk piercing means mounted below said holders and movable relative thereto to penetrate stalks depending from the holders, and means for moving a lath endwise through the apertures made by said piercing means, the combination therewith of means for embracing and providing lateral support for the stalks in the region subjected to stress by the piercing means comprising a pair of jaws disposed below each holder adjacent the piercing means and engageable with opposite sides of a stalk depending from the holder, and means supporting the jaws on the machine for reciprocation longitudinally of the aligned holders and for movement of the jaws of each pair relative to each other into and out of stalk engagement.

9. In a tobacco lathing machine of the type having a series of horizontally spaced aligned holders for receiving and holding the stalks of tobacco, stalk piercing means mounted below said holders and movable relative thereto to penetrate stalks depending from the holders, and means for moving a lath endwise through the apertures made by said piercing means, the combination therewith of means for embracing and providing lateral support for the stalks in the region subjected to stress by the piercing means comprising a pair of jaws disposed below each holder adjacent the piercing means and engageable with the opposite sides of a stalk depending from the holder, means mounting the pairs of jaws for movement longitudinally of the aligned holders and for movement of the jaws of each pair relative to each other into and out of stalk engagement, means biasing the jaws of each pair in one direction relative to each other, and means to move the jaws of each pair relative to each other in the direction opposite said one direction in response to movement of the pairs of jaws as a unit longitudinally of the aligned holders.

References Cited in the file of this patent UNITED STATES PATENTS 

